Efficacy, safety, and optimal timing of single-trocar video-assisted flexible thoracoscopic debridement under local anesthesia for complicated parapneumonic empyema.

OBJECTIVE: Thoracoscopic debridement under local anesthesia is a useful approach for complicated parapneumonic effusion or empyema (CPE) and is a less invasive procedure than video-assisted thoracoscopic surgery under general anesthesia. There are various methods of thoracoscopic debridement under local anesthesia, although the optimal timing of treatment is unknown. The objective of this study was to verify the efficacy and safety of our video-assisted flexible thoracoscopic debridement (VAFTS-D) procedure under local anesthesia, and to investigate the clinical features associated with the success of VAFTS-D. METHODS: The study included 71 consecutive patients with CPE who underwent VAFTS-D. The primary outcome was success of VAFTS-D. We retrospectively analyzed the efficacy and safety of VAFTS-D from the clinical data obtained from hospital medical records, and used univariate logistic analyses to identify potential predictors of the outcome. RESULTS: VAFTS-D was considered successful in 62 of 71 patients (87.3%). Two of the remaining nine patients died and the other seven patients required subsequent operation under general anesthesia. Complications due to VAFTS-D occurred in six patients (8.5%). Duration of empyema < 10 days (P = 0.024) and negative bacterial culture in pleural effusion (P = 0.029) were independently associated with the success of VAFTS-D by univariate logistic regression analysis. CONCLUSION: VAFTS-D might be an acceptable first-line procedure in patients with suspected CPE. VAFTS-D should be performed as early as possible for a successful outcome, and to obtain useful information on the pleural cavity.

Novel fish hypothalamic neuropeptides stimulate the release of gonadotrophins and growth hormone from the pituitary of sockeye salmon.

We recently identified a cDNA encoding three novel fish hypothalamic neuropeptides, having LPXRF-NH(2) from the goldfish brain. In this study, to clarify the physiological functions of these three LPXRFamide peptides (gfLPXRFa-1, -2, and -3), we analysed the localisation and hypophysiotrophic activity of these peptides using sockeye salmon, Oncorhynchus nerka, in which immunoassay systems for several anterior pituitary hormones have been developed. gfLPXRFa-immunoreactive cell bodies were detected in the nucleus posterioris periventricularis of the hypothalamus and immunoreactive fibres were distributed in various brain regions and the pituitary. We also detected gfLPXRFa-immunoreactivity in the pituitary by competitive enzyme-linked immunosorbent assay combined with reversed-phase HPLC. These three gfLPXRFamide peptides stimulated the release of FSH, LH and GH, but did not affect the release of prolactin (PRL) and somatolactin (SL) from cultured pituitary cells. These results suggest that novel fish hypothalamic LPXR-Famide peptides exist in the brain and pituitary of sockeye salmon and stimulate the release of gonadotrophins and GH from the pituitary.

Disturbance of plasma melatonin profile by high dose melatonin administration inhibits testicular maturation of precocious male masu salmon.

We have previously shown that the testicular development of underyearling male masu salmon Oncorhynchus masou reared under a long photoperiod was accelerated by oral melatonin treatment (0.5 mg melatonin/kg body weight/day), suggesting that melatonin mediates photoperiodic signaling. In this study, we further examined the effects of a disturbance in the plasma melatonin profile on gonadal development in underyearling male masu salmon by administering a higher dose of melatonin. Fish randomly selected in June were divided into two groups. They were reared under a light:dark (LD) cycle of 16:8 (lights on 04:00-20:00 hr) and fed with pellets sprayed with melatonin or vehicle twice a day at 08:30 and at 15:30 hr (7.5 mg melatonin/kg body weight/day) until October. Fish were sampled on Day 0, 25, 60, 90 and 120. The plasma melatonin levels were high in the dark phase and low in the light phase in the control group, while they were constantly high with no significant change in the melatonin-treated group. Melatonin treatment had inhibitory effects on the gonadosomatic index and plasma testosterone levels. Pituitary salmon gonadotropin-releasing hormone content and luteinizing hormone content were significantly lower in the melatonin-treated group on Day 60 and 90, respectively. These results indicate that the plasma melatonin profile is important for mediating photoperiodic signals that regulate brain-pituitary-gonadal axis in underyearling precocious male masu salmon.